For a variety of reasons, primarily health, many people in the United States are concerned with achieving and maintaining a particular body weight or range of body weights. Most of these people are concerned about being overweight, and want to reduce. A few are underweight and want to gain. In some areas, particularly California, there are weight control clinics, in which large numbers of patients are checked, counselled, and prescribed for every day.
One of the chief problems associated with achieving and maintaining a particular desired weight is the inclination of the dieter to stray from the diet, an inclination which frequently proves so strong as to lead the dieter to try to deceive not only the doctor, but himself. It is standard practice in weight control regimes now commonly employed to give the dieter a diary and ask that he record immediately everything that he ingests. In practice, it is found that, especially among the obese, the dieter's recall in inaccurate, and he is likely not to be truthful or conscientious in his keeping of the diary. Furthermore, if a person, even a doctor, is a friend of the dieter, that person may not always be truthful either, so as not to embarrass the patient. The dieter frequently becomes discouraged, and understandably, when he has been faithful to the diet and still shows a weight gain which may in fact be the result of water retention. There has been no positive method of determining when dieters have strayed briefly from their diets, and, as has been observed, the weight of a person from day to day varies without any immediate relation to the amount of food he ingests.
It has long been suspected that free acetone is a physiological metabolite. It has been known for many years that diabetics have high levels of blood acetone, and corresponding high levels of acetone in the breath. In uncontrolled but non-comatose diabetics, blood acetone levels range to 75mg%, equal to 2,263mcgm/l in the breath. In 1952 Henderson, Karger and Wrenshall, of the University of Toronto, published a paper in Diabetes, Volume I, No. 3, in which they reported among other observations relating to diabetics, that increases in weight are accompanied by a decrease in acetone exhalation and decreases in weight, by an increase in acetone exhalation.
It is believed that ketones are normal intermediates of fat metabolism, generating small amounts of acetoacetate and 3 hydroxybutyrate. Acetone is formed by the spontaneous and non-enzymatic decarboxylation of acetoacetate. If there is not adequate oxaloacetate from carbohydrates to maintain the Krebs Cycle efficiently, the active acetate from fat is diverted to form ketone bodies which give rise to increased amounts of free acetone. The body oxidizes selectively alcohol, carbohydrates and fats, in that order. Accordingly, the amount of acetone in the blood is a function of fat metabolism. It will increase with exercise, or a diet low in carbohydrates. It will decrease with the ingestion of alcohol or carbohydrates.
The normal acetone content of the blood varies from person to person, so that some norm must be established for each person, but once that is established a deviation from that norm will indicate a deviation in the fat metabolism.
Breath acetone levels from deep lung (aveolar) breath are directly proportional to the acetone levels in the blood. 330cc of deep lung air contain the same amount of acetone as 1cc of blood. However, the amounts involved are so small that there has been no effective way to use the information which has been suggested by researchers in the field.
Even when instruments were devised which were able to detect and measure very small amounts of acetone, variations in breath acetone might constitute an interesting adjunct to the tools used by the doctor, but it would not suggest a method of monitoring diet which would in itself induce compliance with a regimen set for the dieter.
One of the objects of this invention is to provide a method of monitoring the diet which involves an accurate measure of fat loss, which reinforces the dieter's determination, rewarding faithfulness and discouraging cheating.
Another object is to provide such a method which is simple, safe, and quick, saving the time of both the dieter and the physician.
Other objects will become apparent to those skilled in the art in the light of the following description and accompanying drawings.